" Attempt to explain Rendo's success away in any manner that you like.  IMO, the facts of the case speak for themselves far more loudly than any ideology does."

Only problem, Xenophonz, is that facts are just the raw material for further analysis.

Here.. why is Newgrounds, according to Alexa, ranked at #660 while Renderosity hangs around at #10,667? 

Both sites feature a specific kind of computer art - Newgrounds is a community gallery for Flash, while Renderosity is a community gallery for 3D pictures.

Both sites had a wild, anything-goes start.  Early Newgrounds Flash was downright shocking and undergound; Renderosity pictures used to have the content that's now gotten shuffled off to Renderotica.

Newgrounds took the philosophy: "Everything, by everyone."  Their sole criteria for being allowed or removed?  Peer review.  (They do say that you can't have "excessively pornographic" Flashes, but from long experience at Newgrounds, I can assure you that sentence is mostly for show.)

Renderosity took the philosophy: "Become more appealing to the mainstream."  Detailed and specific criteria for what's allowed or not in the Terms of Service.  (Helpful diagrams sometimes!)

Both sites went up in size and traffic over time - sites do that.  They grow.  If they get into a good position, a social gravity takes over; people see a site is big, choose it over others to get more eyeballs and community to work with, and soon enough, the big site is the biggest site.

But why has Newgrounds grown up from such humble, one-man beginnings to become the bleeding edge of Flash entertainment for the world, while Renderosity churns its wheels, a big fish among other 3D sites - much like how Newgrounds is a big fish among other Flash sites - but unable to break through to true prominence?